Method of boring axially-curved holes.



F. A. CLOSE.

METHOD 0F-BOR|NG AXIALLY CURVED HOLES. APPLICATION FILED SEPT- 13, l9l5- 1,1 85, 1 80. Patented May 30; 1916.

[red/Z Clase Quad M438 FRED A. CLOSE, OF UNION'IOWN, PENNSYLVANIA, ASSIGNOR 0F ONE-HALF T0 GEORGE 'W. DURHAM, 0F DETROIT, .MIOHIGAN.

METHOD OF BORING AXIALLY-CURVED HOLES.

Specification of Letters Patent.

Application filed September 13, 1915. Serial No. 50,331.

To all whom it may concern:

Be it known that I, FRED A. Cnosn, a citizen of the United States of America,

residing at Uniontown, in the county of Fayette and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Boring Axially-Curved Holes, of which the following is a specification, reference being had therein to the accompanying drawings.

It is the object of the invention to form curved bores in mechanical structures, and specifically to provide a channel for the reception of a flexible shaft.

To this end the invention comprises the novel method of forming the bore, as here in'after set forth. V

In the drawings I have specifically shown a method of forming curved channels in wheel axle spindles, designed for a flexible shaft connection to a. speedometer.

Figure 1 is a longitudinal section through an. axle spindle illustrating the first operation; Fig. 2 is a similar view showing the manner of forming the curved section of the bore; Fig. 3 is a perspective view of the reaming tool; and Fig. 4 is a diagrammatic view illustrating the operation.

In the present state of the art it is usual to drive cyclometers and speedometers upon motor vehicles from one of the front wheels, and as this wheel is mounted upon a pivotal spindle a flexible drive connectionis essential. One method of forming this flexible drive is by the use of a flexible shafting which passes through a channel in the axle indle. This necessitates the bore through ic spindle, which at the outer end of the latter is in axial alinement therewith, while the inner end is deflected laterally to one side of the pivot. To be operative a flexible shaft when bent must assume a curved form, and therefore the .channel for receiving the shaft must be correspondingly-curved. The usual boring tools are capable of forming straight holes only, and where a channel is formed by intersecting bores there will be ah sitarp angle not suitable for a flexible S a: v I

To form the curved bore I proceed as follows: I first bore an axial channel A, which extends from the outer end of the spindle B part way through the same. I also form an angling bore C which enters the spindle at one side thereof and extends to a point of intersection with the bore A, forming an abrupt angle D. To remove this angle I next insert a revolving reamer E, the length of which varies according to the radius of the curve to be produced. The nose of this reamer F is tapered or pointed, and therefore when-the reamer is forced through one of the bores, such as'C, into the otherbore A, this nose contacting with the sides of the latter bore will-be deflected laterally. This deflection continues as the reamer is forced inward until suflicient material is cut away to admit of the turning of the reamer around the bend and into the axial hole A. The result is a laterally enlarged bore on the inner side of the bend, which is of curved form longitudinally and is therefore suitable for the reception of a flexible shaft.

Patented May 30, 1916.

The tool employed for reaming the curve length revolving reamer through said bores to cut away the sharp angle of intersection.

2. The method of forming curved bores, comprising first forming obliquely intersecting angular bores and then forcing a short length revolving reamer through one bore into the other and deflecting it laterally by the oblique wall of the latter bore to cut away the sharp angle.

3. The method of forming curved bores,

comprising first forming intersecting angurevolving reamer from one channel to the la'r bores, and forcing a tapering nose reother to cut away the inner angle thereof. 10 volving reamer from one bore into the other In testimony whereof I afix my signature to cut away the sharp angle. in presence of two Witnesses.

5 4:. The method of forming curved bores, FRED A. CLOSE.

comprising first boring in opposite direc- Witnesses: tions to form obliquely intersecting straight WILBERT R. ABEL,

channels, and then forcing a tapering nose CARL E. GREGORY. 

